Conventionally, small and thin optical modules which can be implemented in small transceivers used for optical communications are developed. In order to make optical modules thinner, a prism/lens array or the like is used to change the direction of the light emitted from an optical element to the light path of the optical module 90 degrees.
Such a prism/lens array is disclosed as a light-path conversion optical coupling device in the Patent Document 1. The optical coupling device comprises a resin molded body having two surfaces meeting at right angles to each other and a total reflective surface which is at an angle of about 45 degrees to the two surfaces, wherein each of the two surfaces has a plurality of integrally formed collimating lenses and guide holes formed thereon to insert guide pins for connecting with optical connectors and the like.
The Patent Document 2 discloses an optical module comprising: a circuit board which has a level difference of an upper stage and a lower stage in the vertical direction to the surface of the circuit board, an optical waveguide circuit having a waveguide disposed on the upper stage of the circuit board; an optical element disposed on the lower stage of the circuit board; and a glass-made optical reflection element which optically couples the optical waveguide circuit and the optical element.